Head and neck squamous cell carcinoma (HNSCC), the tenth most common cancer in the United States (US), is a collective term that typically includes oral cancer (tongue, buccal cavity, gum, floor of mouth), pharyngeal cancer, and laryngeal cancer. Smoking, alcohol consumption, and human papillomavirus (HPV) seropositivity are all known to be associated with increased risk of HNSCC. However, while neighborhood deprivation and other social factors have been found to be associated with tobacco and alcohol consumption and with sexually transmitted infections (i.e. HPV), the role of such factors on HNSCC and on cancer in general is considerably less clear. Accordingly, the proposed study will utilize an existing HNSCC case-control study to investigate the role of individual-level and community-level social factors on HNSCC risk. The parent study included the recruitment of 705 incident cases and 815 matched controls in the greater Boston metropolitan area from 1999 to 2003. Data include participant characteristics such as age, gender, ethnicity, tobacco and alcohol use, and diet. Additional information will be obtained from the US Census on community-level social and economic factors such as education, employment, poverty, housing, and racial composition. An index of neighborhood deprivation and an index of community-level socio-economic status will be developed to address the following specific aims (Messer et al, 2006, Roberts et al, 2004): (1) investigate the role of individual and community-level social factors on HNSCC risk and disease survival, (2) determine whether individual and community-level social factors are associated with tobacco and alcohol consumption, (3) determine whether individual and community-level social factors are associated with sexual behavior and HPV seropositivity, and (4) determine whether individual and community-level social factors modify the effect of smoking, drinking, and HPV on HNSCC risk. These objectives are consistent with the goals of the National Cancer Institute (NCI) and relate to the NCI's strategic plan with respect to the stated need for additional research on cancer health disparities. Additionally, the existing infrastructure of the parent study presents a unique and cost-effective opportunity to investigate the role of neighborhood deprivation and community-level socio-economic status on HNSCC risk. With access to the data from the parent study, access to the extensive resources at Boston University, the support of an excellent mentoring team, and a carefully designed research training plan, the applicant is ideally positioned to conduct the proposed research. The mentoring team has expertise in environmental and social epidemiology, biostatistics, and exposure biology and is committed to providing the necessary guidance during the training period. The long term goal of the applicant is develop an active research program in the areas of environmental and social epidemiology, such that the proposed research will not only provide valuable insights into the role of neighborhood deprivation and community-level socio-economic status on HNSCC risk, but also play a key role in the development of a promising research career.